The Obama administration isn't the first to face criticism of using the Internal Revenue Service as a political hit squad. Since the advent of the federal income tax about a century ago, several presidents – or their zealous underlings – have directed the IRS to turn its formidable police powers on political rivals.

As President Coolidge's Treasury secretary, Andrew Mellon ordered an IRS audit of a rival, only to find the Franklin Roosevelt administration, later, doing the same to him. President Nixon was caught on tape ordering IRS field audits of dozens of people deemed to be his political enemies. In other cases, a direct line of accountability to the president is not so clear. But whether directly ordered by a president or not, the IRS field audit has long been an option that gives new meaning to the term "bully pulpit."

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President Calvin Coolidge (R)

Andrew Mellon, Treasury secretary under President Coolidge, used the tax code to target a political rival: Sen. James Couzens (R) of Michigan. The tactic eventually backfired on Mellon, but it set a precedent for future administrations to use the IRS to attack political adversaries.

There's no evidence that President Coolidge personally directed the IRS to punish political enemies. But his Treasury secretary – banker and industrialist Andrew Mellon – had no such scruples. Secretary Mellon's target was Sen. James Couzens (R) of Michigan, a former general manager of the Ford Motor Co. and a fellow millionaire who launched a congressional probe of tax rebates given to Mellon companies during World War I. The investigation revealed that Mellon had misrepresented the extent to which he was still involved in the management of his own companies, such as Alcoa, prompting calls for his resignation on the eve of the 1924 presidential vote.

After Coolidge was reelected, the Treasury under Mellon reopened the senator's 1919 tax return and ordered Couzens to pay $11 million in back taxes. But that wasn't the end of it. An appeals board eventually reversed that outcome and concluded that, in fact, Couzens was entitled to a refund. "This decision was the greatest humiliation Mellon had yet suffered at the Treasury," wrote biographer David Cannadine.

However, the incident set a template for future administrations for using the tax code to attack political opponents – a weapon that would be turned against Mellon himself in the Roosevelt administration.